reason: Verify category maintenance against backend core module expectations.


reason: Verify category DAO/service contracts and book-category integrity behavior.


reason: Verify validation and safe fallback messages.


reason: Verify layer boundaries and test expectations.


reason: Verify JSP/CSS work stays in the approved frontend stack.


reason: Verify page composition uses existing forms/tables/navigation patterns.


reason: Verify JSP safety, empty states, errors, and permission-specific navigation.